Coupling between neuronal function and metabolism. Increased intracellular sodium caused by monensin stimulated the sodium pump to consume ATP in cultured neurons, in relation to rapid upregulation of transcription of mitochondrial-derived subunits of enzyme for oxidative phosphorylation. There is very rapid coupling between electrical activity, ATP consumption and oxidative-phosphorylation in mitochondria (Mehrabian et al. 2005).[unreadable] [unreadable] Decreased AA metabolism in sympathetically denervated rat heart. The AA incorporation rate from plasma was reduced 60-84% in rats subjected to cardiac sympathetic denervation (Patrick et al. 2005). PLA2 activity also was reduced. Thus, cardiac AA metabolism is intimately connected with its sympathetic activity[unreadable] [unreadable] Ischemic changes. Five-minutes of cardiac ischemia in rats decreased heart unesterified fatty acid concentrations but increased concentrations of several long- and short-chain acyl-CoA species (Maoz et al. 2005). [unreadable] [unreadable] Low liver conversion rate of alpha-linolenic to docosahexaenoic acid in awake rats on a high-docosahexaenoate-containing diet. We quantified the rates of incorporation of alpha-linolenic acid (alpha-LNA; 18:3n-3) into "stable" lipids (triacylglycerol, phospholipid, cholesteryl ester) and the rate of conversion of ?-LNA to docosahexaenoic acid (DHA; 22: 6n-3) in the liver of awake male rats on a high-DHA-containing diet after a 5-min intravenous infusion of [1-14C]alpha-LNA. A lower limit for the DHA synthesis rate from alpha-LNA equaled 15.8 nmol/s/g x 10-4 (Igarashi et al. 2006).